Coated article with silicon nitride inclusive layer adjacent glass

The present invention is a solution according to the subject matter of the independent claim 1. Specific optional variants are given in the dependent claims.

BRIEF DESCRIPTION OF EXEMPLARY EXAMPLES OF THIS INVENTION

According to certain embodiments of the present invention, the titanium oxide layer in contact with the glass substrate in the exemplary coated article of 10 / 400,080 is removed. It has been surprisingly found that the removal of titanium oxide in the layers provides an improvement in staining and a significant improvement in mechanical strength (note: other changes may be made to specific coatings according to 10 / 400,080). In relation to the color, removal of the titanium oxide layer adjacent to the glass substrate surprisingly provided a more neutral color of the coated article. The reason for the remarkable improvement in strength is unknown, but it has been found that it may be related to the problem of adhesion between silicon nitride and titanium oxide layers. Undesirable stresses between layers can be eliminated by removing the titanium oxide layer, thereby providing a significant improvement in strength. In some embodiments, removal of the titanium oxide layer adjacent to the glass substrate may also provide improved infrared blocking properties of the coating, while increasing light transmission.

Thus, according to certain embodiments of the present invention, removal of the titanium oxide layer adjacent to the glass substrate provides at least one of the following benefits: (a) improved strength, (b) improved color, and / or (c) improved sun / optical properties.

In certain example embodiments of this invention, a heat-treatable coated article is obtained having a ratio of light transmittance (TY, Lta or Tvis) to sheet resistance (Rs) (i.e., Tvis / Rs ratio) after heat treatment of at least 25, more preferably at least 32, even more preferably at least 34 and most preferably at least 36.

In other embodiments of the present invention, it has surprisingly been found that coated articles according to certain embodiments of the present invention exhibit better heat workability compared to other known coatings. For example, it has surprisingly been found that coated articles according to certain embodiments of the present invention can be heat treated at a temperature of about 650 degrees C for 12 minutes without loss of light transmission above 2%. In other words, if the coated article is heat treated at about 650 degrees C for 12 minutes, the coated article retains about 98% of its pre-heat light transmission.

EP 1673313

Particular embodiments of the present invention relate to a coated article comprising a multilayer coating formed on a glass substrate, such that the multilayer coating consists of the following elements, listed from the glass substrate outwards: a layer containing silicon nitride formed directly on and in contact with the glass substrate; a layer comprising zinc oxide formed directly on and in contact with the layer containing silicon nitride; a silver-containing layer formed directly on and in contact with the zinc oxide-containing layer; a layer of dielectric material containing metal oxide; another layer containing silver; another layer of dielectric material. The coated article may be heat treated.

Certain other embodiments of the present invention relate to a heat treatable coated article comprising a multilayer coating formed on a glass substrate, such that the multilayer coating consists of the following elements, listed from the glass substrate outwards: a layer containing silicon nitride formed directly on and in contact with the glass substrate; a layer comprising at least one metal oxide; a layer comprising silver formed directly on and in contact with the layer comprising at least one metal oxide; at least one layer of dielectric material; if the coated article is heat treated at a temperature of about 650 degrees C for 12 minutes (example conditions), the coated product retains approximately 98% of its pre-heat light transmission.

SHORT DESCRIPTION OF ILLUSTRATIONS

Fig. 1 is a cross-sectional view of a single coated article according to an embodiment of the present invention - the materials and specific layers shown in the illustration are illustrative only.

Fig. 2 is a cross-sectional view of the coated article of Fig. 1 used in an IG unit according to an embodiment of the present invention.

Fig. 4 is a cross-sectional view of the coated article of Fig. 1 used in a laminated vehicle windshield according to an embodiment of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EXAMPLES OF THIS INVENTION

The following are detailed references to the illustrations in which the numerical values ​​indicate the same elements.

Coated products can be used in automotive vehicle glazing, e.g., tempered laminated windshields, monolithic glazing, and double glazing, and / or other suitable applications that include one or more glass substrates.

According to certain embodiments of the present invention, the titanium oxide layer adhered to the glass substrate of the exemplary coated article of 10 / 400,080 described in the description section of the prior art is removed. It has been surprisingly found that the removal of the titanium oxide layer provides an improvement in staining and a significant improvement in mechanical strength. With regard to color, removal of the titanium oxide layer adjacent to the glass substrate unexpectedly provided a more neutral color (i.e. reflective color on the glass substrate side). In addition, thermal stability during heat treatment can be significantly improved.

The reason for the remarkable improvement in strength is unknown, but it has been found that it may be associated with the problem of adhesion between silicon nitride and titanium oxide layers in a coated article according to 10 / 400,080. In particular, internal stresses in the titanium oxide layer and in the silicon nitride layer of the coating according to 10 / 400,080 can be a problem, especially after heat treatment. After heat treatment, these stresses may cause delamination of the coatings as a result of a standard brush test, thus indicating a lack of strength. After removing the oxide layer

EP 1673313 titanium, the silicon nitride-containing layer is applied directly to the glass substrate, and the problematic connection between the titanium oxide and silicon nitride layers does not occur. Unexpectedly, removing the seemingly problematic layer boundary (by removing the titanium oxide layer) provides a significant improvement in strength, in particular after heat treatment. In some embodiments, removal of the titanium oxide layer adjacent to the glass substrate may also provide improved infrared blocking properties of the coating, while increasing light transmission.

Thus, according to certain embodiments of the present invention, removing the titanium oxide layer adhered to the glass substrate from the coating according to 10 / 400,080 provides one or more of the benefits listed below: (a) improved strength, (b) improved color, (c) improved properties sunscreen and optical, and / or (d) improved thermal stability during heat treatment. Coated articles may be heat treated in various embodiments of the present invention, wherein in certain embodiments, the improvement in strength is particularly evident after heat treatment.

In certain example embodiments of this invention, a heat-treatable coated article is obtained having a ratio of light transmittance (TY, Lta or Tvis) to sheet resistance (Rs) (i.e., Tvis / Rs ratio) after heat treatment of at least 25, more preferably at least 32, even more preferably at least 34 and most preferably at least 36. The higher the ratio, the better the overall functionality of the coated article ensuring both good sunscreen properties (e.g. ability to reflect and / or absorb solar radiation) and high light transmission. In other words, high light transmission can be achieved without affecting sunscreen properties. In certain embodiments, in combination with one or more Tvis / Rs ratios, the coated product is heat treated by a method suitable for commercial use, such that: (i) the value of ΔΕ * (the coefficient of transmission and / or reflection from the side of the glass substrate) is not greater due to heat treatment, than about 8.0, more preferably no greater than about 5.0, even more preferably not greater than about 4.0, even more preferably not greater than about 3.0, sometimes not more than 2.5; and / or (ii) the coating comprises at least one contact layer comprising at least one metal (e.g. Ni, NiCr, Cr, Ti, TiO, NiCrOx, ZnO, ZnAlO, Nb, mixtures thereof etc.) between the reflective layer for infrared radiation (e.g. silver layer) and a layer of dielectric material protecting the reflective layer for infrared radiation during heat treatment. In addition, in some embodiments of the present invention, the Tvis / Rs ratio of coated products has a value before heat treatment, preferably at least 22 before heat treatment, more preferably at least 25 before heat treatment, most preferably at least 28 before heat treatment. It should be noted that in some embodiments of the present invention, coated articles need not have any of the Tvis / Rs ratios listed (although they are present in many preferred embodiments). In addition, parameters such as Rs, Tvis / Rs and ΔE * are usually measured before lamination in embodiments of laminated coated products.

Factors that can affect an unexpectedly high Tvis / Rs ratio include one or more of the following factors: exemplary layer arrangement described below, exemplary stoichiometric ratio of layers, exemplary layer thicknesses, use of a layer containing silicon nitride with high Si content under at least one reflective layer red radiation and / or the application of different layers containing zinc oxide with different oxygen partial pressures. For example, in certain embodiments, it has been surprisingly found that the use of a combination of a layer containing a high Si content silicon nitride and a layer containing zinc oxide (e.g., ZnO, ZnAlOx or ZnO containing other elements) under the silver-containing layer allows silver deposition (e.g.

EP 1673313 by sputtering, etc.) in a manner that reduces the sheet resistance compared to cases in which other materials are used under the silver layer. In some embodiments, it has been found that the use of a layer or layers containing a high Si content (SixNy) silicon nitride allows a significant increase in the Tvis / Rs ratio after heat treatment (e.g., curing, hardening and / or heat bending). Although it is not clear why the high Si SixNy layer works in this way, it is likely that the presence of free Si in the high Si silicon nitride layer may allow the migration of certain atoms, such as sodium (Na) atoms, outwards towards from the glass substrate 1 during heat treatment through a layer containing silicon nitride with a high Si content before it reaches the silver layer and causes damage to it. Oxidation caused by heat treatment allows for increased light transmission, and the High Si SixNy layer or layers reduce the extent of damage to the silver layer or layers during heat treatment, allowing a significant reduction in sheet resistance (Rs).

In Fig. 1 shows a side cross-section of a coated article according to an embodiment of the present invention that does not limit the scope of the present invention. The coated article includes substrate 1 (e.g. transparent, green, brown or green-blue glass substrate with a thickness of 1.0-10.0 mm, more preferably 1.0-3.5 mm and a multilayer coating (or layer system) 27 directly or indirectly applied to the substrate 1. The coating (or layer system) 27 may include a dielectric silicon nitride layer 4, which may be a Si3N4 layer or a layer with a high Si content (which may be doped with Al, stainless steel, etc.), first contact layer 7, which contacts and protects the reflective layer for infrared radiation 9, first conductive layer and potentially metallic reflective layer for infrared radiation 9, first upper contact layer 11, which contacts and protects the reflective layer for infrared radiation 9, dielectric material layer 13, another layer containing silicon nitride 14 (stoichiometric ratio or high Si content), the second bottom contact layer 17, which contacts and protects the reflective layer for infrared radiation IR 19, the second upper contact layer 21, which contacts and protects the upper reflective layer for infrared radiation 19, a layer of dielectric material 23 and a final protective layer of dielectric material 25. Contact layers 7, 11, 17 and 21 are in contact with at least one reflective layer for infrared radiation (e.g. Ag layer). Said layers 4-25 constitute a low-emission coating 27 applied to a glass or plastic substrate 1.

Compared to the coated article of 10 / 400,080, it has surprisingly been found that removal of the titanium oxide layer adjacent to the glass substrate is advantageous for the reasons discussed above. Thus, in certain example embodiments of this invention according to Fig. 1, layer 4 containing silicon nitride is applied directly to the glass substrate. The silicon nitride layer 4 may be doped with Al, B, stainless steel and similar additives in various embodiments of the present invention (e.g. from 0-15%, more preferably from 1-15%, and most preferably from 5-15%). As described below, the layer containing silicon nitride 4 is oxidized and a high Si content may be advantageous for the reasons given. In some embodiments, layer 14 may also contain silicon nitride with a high Si content.

The layer containing silicon nitride 4 is oxidized to form silicon oxynitride. Silicon oxynitride layer 4 may have different refractive indices of "n" - e.g. from about 1.5 to 2.0, more preferably from 1.55 to 2.0 and most preferably at least 1.6. For laminated components, such as laminated vehicle windshields, layer 4 silicon nitride may have, in some embodiments, a refractive index "n" of 1.85 to 2.0, more

EP 1673313 preferably from 1.9 to 2.0, in order to avoid loss of permeability due to lamination (due to different refractive indexes of the material in contact with the surface of the layer, such as 1.57 for PWB (polyvinyl butyral) instead of air (1.0), higher coefficient on both boundary surfaces can reduce reflection loss). Furthermore, the silicon oxynitride layer 4 may have a "k" value (550 nm) of no more than about 0.04, more preferably no more than about 0.03. In certain embodiments, the value "k" is from 0.01 to 0.03, most preferably about 0.02. In certain example embodiments of this invention, the silicon nitride layer 4 may be converted to silicon nitride during heat treatment, to some extent absorbing water from the glass surface, which is a residue from previous processes (thus, the layer prior to heat treatment is silicon nitride).

In addition, in certain embodiments, it has surprisingly been found that the use of a combination of a layer containing a high Si (4 and / or 14) silicon nitride and a layer containing zinc oxide (e.g., ZnO, ZnAlOx) (7 and / or 17) under the layer containing silver (9 and / or 19) enables the application of silver (e.g. by cathode sputtering, etc.) in a manner that reduces sheet resistance compared to cases where other materials are used under the silver layer. In some embodiments, it has been found that the use of a layer or layers containing a high Si content (SixNy) silicon nitride allows a significant increase in the Tvis / Rs ratio after heat treatment (e.g., curing, hardening and / or heat bending). It is likely that the presence of free Si in the layer containing high Si (4 and / or 14) silicon nitride can stop the migration of certain atoms, such as sodium (Na) atoms outwards from the glass substrate 1 during heat treatment through the layer containing silicon nitride with high Si content before it reaches the silver layer and causes damage. Embodiments of claim 1 are embodiments of the present invention, while embodiments other than of claim 1 are reference embodiments.

In certain embodiments, one or both of the silicon nitride layers with potentially high Si 4 and / or 14 content may be SixNy layers in which x / y are between 0.80 and 1.0 (higher x / y ratios may cause an undesirable increase in turbidity). In addition, in certain embodiments where a small amount of oxygen is present in layer 4 and / or 14, before and / or after heat treatment, SixNy layers with high Si (4 and / or 14) may have a refractive index of " n "of at least 2.05, more preferably at least 2.07, even more preferably at least 2.10 and most preferably about 2.15 to 2.25 (e.g. about 2.20) (eg, 632 nm) (note: at the stoichiometric ratio Si3N4, the factor "n" is 2.04). SixNy layers with a high Si content (4 and / or 14) in specific embodiments may have a specific absorption coefficient "k" of at least 0.001, more preferably at least 0.003 (note: at the stoichiometric ratio Si3N4, specific absorption coefficient "k" has a value of 0). In some embodiments, SixNy layers with high Si 4 and / or 14 content have a specific absorption coefficient "k" of 0.01 to 0.02.

The reflective layers for infrared radiation 9 and / or 19 are preferably metallic and / or conductive and may contain or consist of silver (Ag), gold or other suitable reflective materials for infrared radiation. Reflective layers for infrared radiation provide low-emission properties and / or good sun-protection properties of coating 27. In certain example embodiments of this invention, the reflective layers for infrared radiation may be slightly oxidized.

In certain embodiments, the upper contact layers 11 and 21 may be made of or contain nickel oxide (Ni), chromium oxide or nickel oxide, such as chromium nickel oxide (NiCrOx) or other suitable materials. Use in these layers

- EP 1673313

NiCrOx provides improved strength. In certain example embodiments of this invention, the NiCrOx layers may be fully oxidized (i.e. in stoichiometric ratio) or in other embodiments, they can be oxidized in a range of about 50%. In certain preferred embodiments, NiCrOx in these layers may be in a ratio lower than stoichiometric (oxygen deficiency). Although NiCrOx is the preferred contact layer material, it is obvious to those skilled in the art that other materials may be used. According to various embodiments of the present invention, contact layers 11 and / or 21 (e.g. made of or containing NiCrOx) may undergo oxidation to varying degrees. A different degree of oxidation means that the extent of oxidation in the layers varies in at least part of the thickness of the layer, such that, for example, the contact layer may be oxidized to a lesser extent on the contact surface with the adjacent infrared reflective layer than in the remote or more distant contact layer / furthest from the adjacent infrared reflective layer. Descriptions of contact layers 11 and 21 oxidizing to varying degrees are given in US Patent No. 6,576,349.

In certain embodiments of the invention, the lower contact layers 7 and 17 contain zinc oxide (e.g., ZnO). In certain embodiments, the zinc oxide may contain Al (e.g., forming ZnAlO) or other elements. In certain alternative embodiments of the present invention, another layer (e.g., NiCr oxide, Ni oxide, or other compounds) may be formed between the layer comprising zinc oxide 17 and the nearest reflective layer for infrared radiation 19.

In certain example embodiments of this invention, the dielectric material layer 13 forms a layer connecting the two halves of the coating 27 and is made of or comprises tin oxide. Other dielectric materials may be used as layer 13.

The dielectric layers 23 and 25 provide an improvement in the resistance of the coating 27 to ambient conditions, as well as may affect its color. In certain embodiments, the dielectric material layer 23 may be made of or comprise tin oxide (e.g. SnO2), but other materials may also be used. In certain example embodiments of this invention, the top layer of dielectric material may be made of or contain silicon nitride (e.g., Si3N4), other materials such as titanium dioxide, silicon nitride, tin oxide, zinc oxide, oxide may be used niobium etc. materials such as dielectric materials with a refractive index "n" in the range from 1.6 to 3.0. According to certain embodiments of the present invention, layer 23 (and / or other layers according to Fig. 1) may be omitted.

Other layers may also be applied. Furthermore, according to specific embodiments of the present invention, selected layers of coating 27 may be removed, while other layers may be formed between different layers or different layers may be separated by other layers formed between separated sections.

In Fig. 2 a system of coatings or layers 27 formed on the surface # 2 of the insulating glass is shown. Coatings 27 according to any embodiment can be used in the double glazing according to Fig. 2. In order to distinguish between the "inner surface" and the "outer surface" of the IG unit, the diagrams show the sun symbol 29 outside the IG unit. The double glazed unit covers the outer pane of glass or glass (i.e. substrate 1 according to Fig. 1) and the inner pane of glass or glass 31. Two glass substrates (e.g. float glass with a thickness of 1-10 mm) are sealed at the edges with standard sealant and / or spacers 33 and can be equipped with a standard drying tape (not shown). Windows can be mounted in standard window or door frames. By sealing the edges of the glass and optionally replacing the air in the insulation space (or chamber) with a gas such as argon, a high insulating glass unit is formed. The gas in the insulating space 30 may optionally be at a pressure less than atmospheric pressure (3o space)

EP 1673313 can optionally be filled with gas), this is not necessary in all embodiments. A layer 27 according to is formed on the inner side of the substrate 1

Fig. 2, wherein the present invention is not limited to this case (e.g., in other embodiments of the present invention, the coating 27 may be formed on the inner surface of the substrate 31).

Fig. 3 shows the coating of Fig. 1 used in the context of laminated glass, such as vehicle windshields along with heat treated and bent glass substrates 1 and 31. According to Fig. 3, the coating 27 is formed on surface # 3, with the present the invention is not limited in this respect. In other cases, a coating may be formed on the inner surface of another substrate.

According to Fig. 1, although different thicknesses may be used in different embodiments, exemplary thicknesses and materials of the respective layers on the glass substrate 1 in the embodiment of Fig. 1 are as follows from the glass substrate towards the outside:

Table 2 (Exemplary materials / thicknesses; Embodiment according to Fig. 1)

<td>Layer</td><td>Favorable range (A)</td><td>More favorable (A)</td><td>Example (A)</td>

<td>SixNy (layer 4)</td><td>50-450 A</td><td>100-200 A.</td><td>140 A.</td>

<td>ZnOx (layer 7)</td><td>10-300 A.</td><td>40-150 A.</td><td>100 A.</td>

<td>Ag (layer 9)</td><td>50-250 A</td><td>80-120 A.</td><td>95 A.</td>

<td>NiCrOx (layer 11)</td><td>10-100 A.</td><td>20-50 A.</td><td>37 A.</td>

<td>SnO2 (layer 13)</td><td>0-1.000 A</td><td>350-800 A.</td><td>550 A.</td>

<td>SixNy (layer 14)</td><td>50-450 A</td><td>90-200 A.</td><td>115 A.</td>

<td>ZnOx (layer 17)</td><td>10-300 A.</td><td>40-150 A.</td><td>100 A.</td>

<td>Ag (layer 19)</td><td>50-250 A</td><td>80-220 A.</td><td>95 A.</td>

<td>NiCrOx (layer 21)</td><td>10-100 A.</td><td>20-50 A.</td><td>37 A.</td>

<td>SnO2 (layer 23)</td><td>0-750 A.</td><td>70-200 A.</td><td>105 A.</td>

<td>Si3N4 (layer 25)</td><td>0-750 A.</td><td>120-320 A</td><td>185 A.</td>

According to certain embodiments of the present invention, the total thickness of the combined layers 4 and 7 is less than the total thickness of the combined layers: (a) layers 13-17, and layers (b) 23-25. According to certain embodiments, the total thickness of the combined layers 4 and 7 is not more than about 90% of the thickness of the combined layers 23-25, more preferably not more than about 80% of this thickness. According to certain embodiments, the total thickness of the combined layers 4 and 7 is not more than about 50% of the thickness of the combined layers 13-17, more preferably not more than 40% of this thickness and most preferably not more than 33% of this thickness.

According to certain embodiments of the present invention, coated articles may have the low-emission properties listed in Table 3, measured monolithically (before optional heat treatment). The sheet resistance (Rs) includes all infrared reflective layers (e.g., silver layers 9, 19) in the coating, unless otherwise specified.

- EP 1673313

Table 3: Low emission / sun protection properties (monolithic; before heat treatment)

<td>Property</td><td>General</td><td>More favorable</td><td>Most favorable</td>

<td>R_s (Ω / square)</td><td>&lt;= 5.0</td><td>&lt;= 3.5</td><td>&lt;= 3.0</td>

<td>en:</td><td>&lt;= 0.07</td><td>&lt;= 0.04</td><td>&lt;= 0.03</td>

<td>Tvis / Rs:</td><td>&gt; = 20</td><td>&gt; = 22</td><td>&gt; = 25</td>

According to certain embodiments of the present invention, coated articles may have the following properties, measured, for example, monolithically, after heat treatment:

Table 4: Low emissivity / sun protection (monolithic; after treatment

<td colspan="4">heat)</td>

<td>Property</td><td>General</td><td>More favorable</td><td>Most favorable</td>

<td>R_s (Ω / square)</td><td>&lt;= 4.5</td><td>&lt;= 3.0</td><td>&lt;= 2.5</td>

<td>en:</td><td>&lt;= 0.07</td><td>&lt;= 0.04</td><td>&lt;= 0.03</td>

<td>Tvis / Rs:</td><td>&gt; = 25</td><td>&gt; = 30</td><td>&gt; = 32 (or&gt; = 34 or 36)</td>

Accordingly, quite high Tvis / Rs values ​​in Tables 3 and 4 indicate an excellent combination of high light transmittance and good sunscreen properties (e.g., infrared reflection).

In addition, coated articles including coatings 27 according to certain embodiments of the present invention may have the following optical properties (e.g. if the coating or coatings are applied to a glass substrate of transparent sodium silicate glass 1 to 10 mm thick (heat treated or not). In Table 5, all parameters are measured monolithically, unless otherwise specified. In Table 5 below, the RgY value is the light reflection coefficient on the glass substrate side (g) of the monolithic product, while RfY is the light reflection coefficient on the monolithic product side on which the coating / layer (f) is formed (i.e. coating 27). Δ * values ​​due to heat treatment (e.g. curing, hardening and / or thermal bending). All measurements of the D65 illuminant parameters were made at an angle of 10 degrees.

Table 5: Optical properties (monolithic - heat treatment)

<td>Property</td><td>General</td><td>More favorable</td>

<td>Tvis (or TY) (illuminator D65):</td><td>&gt; = 70%</td><td>&gt; = 75%</td>

<td>a * t (illuminator D65):</td><td>-4.0 to +1.0</td><td>-3.0 to 0.0</td>

<td>b * t (illuminator D65):</td><td>-3.0 to +4.0</td><td>-1.0 to 3.0</td>

<td>L * t (illuminator D65):</td><td>85 to 95</td><td>88 to 93</td>

<td>RgY (illuminator D65):</td><td>1 to 10%</td><td>3 to 9%</td>

<td>a * g (illuminator D65):</td><td>-4.5 to +2.0</td><td>-3.0 to 0.0</td>

<td>b * g (illuminator D65):</td><td>-5.0 to +10.0</td><td>-4.0 to +8.0</td>

<td>L * g (illuminator D65):</td><td>25 to 40</td><td>28 to 34</td>

<td>RfY (illuminator D65):</td><td>1 to 10%</td><td>1 to 8%</td>

<td>a * f (illuminator D65):</td><td>-14.0 to 10.0</td><td>-11.0 to 3.0</td>

- EP 1673313 b * f (illuminator D65): L * f (illuminator D65):

-9.0 to 20.0 to 35

ΔΕ \ (transmittance factor): &lt;= 8.0

ΔΕ% (reflection coefficient from the side &lt;= 8.0 glass substrate):

-7.0 to 12.0 to 32 &lt;= 5.0, 4.0, 3.0 or 2.5 &lt;= 5.0, 4.0, 3.0 or 2.5

Optical turbidity: R_s (Ω / square)

&lt;= 0.4 &lt;= 5.0 &lt;= 0.35, or &lt;= 0.25 &lt;= 3.0, or &lt;= 2.5

In other embodiments, the light transmittance factor may be lower (e.g., 60% or even 40-50% in some cases).

The ΔE * values ​​are important in determining whether there is the possibility of matching or practical color matching after heat treatment, in the context of specific embodiments of the present invention. The color is described by reference to the standard values ​​a *, b *. The term Δa * indicates the extent to which the color value a * changes due to heat treatment (this also applies to Δb *). If the color changes too much due to heat treatment (e.g. if the ΔE * value exceeds 10), the product may not be authorized. A very high ΔE * value may also indicate damage to the Ag layer during heat treatment and / or optical turbidity.

The term ΔE * (and ΔE) is well known in the art along with various methods for determining it, see ASTM 2244-93, as well as Hunter et al., The Measurement of Appearance, ed. 2, chapter 9, page 162 et seq. (John Wiley &amp; Sons, 1987). According to the state of the art, the value of *E * (and ΔE) is an appropriate way of expressing the change (or lack thereof) of the reflection coefficient and the transmittance (and thus also the color) of the product before and after heat treatment. The ΔE value can be calculated using the "ab" method or the Hunter method (denoted by the symbol "H"). The ΔE value corresponds to the Hunter Lab scale L, a, b (or L_h, and_h, b_h). Accordingly, the value of ΔE * corresponds to the CIE LAB L * scale, a *, b *. Both values ​​can be used and are equivalent within the scope of the present invention. For example, according to Hunter and others, the rectangular coordinate method / scale method (CIE LAB 1976) known as the L *, a *, b * scale, such that:

L * to (CIE 1976) brightness units a * to (CIE 1976) red-green units b * to (CIE 1976) yellow-blue units distance ΔE * between L *_about and*_about b *_about and L *₁ and*₁ b *₁ is:

ΔΕ * = {(AL *)²+ (Aa *)² + (ńb *)²}^2.1 where:

AL * = L *! - L *_aboutAa * = a * and a *₀

Δ5 * = 5 * j _b *₀ (1) (2) (3) (4) the subscript "o" means the coating (or coated article) prior to heat treatment, while the subscript "1" means the coating (coated article) after heat treatment; and numerical values ​​(e.g., a *, b *, L *) are calculated using the coordinate method (CIE LAB 1976) L *, a *, b *. In a similar way, the value of ΔE can be calculated from equation (1) by replacing a *, b *, L * with Hunter Lab values ​​ah, bh, Lh. Equivalent numbers converted to calculated values ​​are also included in the scope of the present invention and the quantification of the ΔE * values

EP 1673313 by any other method using the same concept of ΔE * values ​​as given above.

According to certain embodiments of the present invention, as explained above, coated articles may have a value ΔE * (transmittance and / or reflection from the glass substrate side) due to heat treatment is not greater than about 8.0, more preferably not greater than about 5.0, more preferably not more than about 4.0, even more preferably not more than about 3.0, in some cases not more than about 2.5. These values ​​indicate that coated products can be heat treated using a commercial method. In exemplary laminated products, the ΔE * value is typically measured prior to lamination.

In addition, coated products with coatings 27 according to certain embodiments of the present invention may have the following properties (e.g. coatings formed on surface # 3 (or other suitable surface) of the heat treated laminated vehicle windshield according to Fig. 3). In certain embodiments, the glass substrates can be transparent glass substrates about 2.1 mm thick together with an intermediate layer PWB (polyvinylbutyral) about 0.76 mm thick. Again, all illuminant D65 parameters were measured at an angle of 10 degrees. Because the coating is formed on surface # 3 according to Fig. 3, measurements from the glass substrate side should be made from the laminate side, which is inside the vehicle during operation.

Table 6: Properties (laminated windshield - heat treatment)

<td>Property</td><td>General</td><td>More favorable</td>

<td>Lta (illuminant A, 2 degrees):</td><td>&gt; = 70%</td><td>&gt; = 75%</td>

<td>Tvis (or TY) (illuminator D65):</td><td>&gt; = 70%</td><td>&gt; = 75%</td>

<td>a * t (illuminator D65):</td><td>-5.0 to +1.0</td><td>-3.5 to 0.0</td>

<td>b * t (illuminator D65):</td><td>-3.0 to +5.0</td><td>-1.0 to 3.5</td>

<td>L * t (illuminator D65):</td><td>85 to 95</td><td>88 to 93</td>

<td>RgY (illuminator D65):</td><td>1 to 11%</td><td>3 to 9%</td>

<td>a * g (illuminator D65):</td><td>-4.5 to +2.0</td><td>-3.0 to 0.0</td>

<td>b * g (illuminator D65):</td><td>-12.0 to +10.0</td><td>-10.0 to +8.0</td>

<td>L * g (illuminator D65):</td><td>30 to 40</td><td>34 to 37</td>

<td>RfY (illuminator D65):</td><td>1 to 11%</td><td>1 to 10%</td>

<td>a * f (illuminator D65):</td><td>-10.0 to 5.0</td><td>-5.0 to 3.0</td>

<td>b * f (illuminator D65):</td><td>-10.0 to 20.0</td><td>-8.0 to 12.0</td>

<td>L * f (illuminator D65):</td><td>30 to 40</td><td>34 to 37</td>

<td>Optical turbidity:</td><td>&lt;= 0.4</td><td>&lt;= 0.35, or &lt;= 0.33</td>

<td>Rsolar (ISO 9050):</td><td>&gt; = 25</td><td>&gt; = 29</td>

<td>Tsolar (TS):</td><td>&lt;= 47</td><td>&lt;= 45</td>

EXAMPLE 1

Example 1 below is exemplary only and does not limit the scope of the present invention in any way. The following examples include the described arrangement of layers, from the transparent glass substrate outwards.

- EP 1673313

Table 7: Layout of examples

<td>Layer</td><td>Thickness</td>

<td>Glass substrate</td><td>about 2 to 2.3 mm</td>

<td>Si x N y</td><td>140 A.</td>

<td>ZnAlO x</td><td>100 A.</td>

<td>Ag</td><td>95 A.</td>

<td>NiCrO</td><td>37 A.</td>

<td>SnO2</td><td>550 A.</td>

<td>Si x N y</td><td>115 A.</td>

<td>ZnAlO x</td><td>100 A.</td>

<td>Ag</td><td>95 A.</td>

<td>NiCrO</td><td>37 A.</td>

<td>SnO2</td><td>105 A.</td>

<td>Si3N4</td><td>185 A.</td>

In addition, as described, the two lower layers of silicon nitride (SixNy) (doped with Al in this example) are in a non-stoichiometric ratio and have a high Si content. Accordingly, it was found that a combination of a layer containing a high Si content silicon nitride and a layer containing zinc oxide (e.g. ZnAlOx) under the silver-containing layer allows silver to be deposited in a way that reduces sheet resistance (desirable) relative to other materials under the silver layer. According to certain embodiments of the present invention, silicon nitride (SixNy) layers having a high Si content allow a significant increase in the Tvis / Rs ratio after heat treatment.

The cathode sputtering process used to form the coated article of Example 1 is described below, the speed of the TerraG flat glass coating machines is 0.5 m / min. Below, Ar, O and N refer to the respective flows of these gases in the coating machine in sccm units. Pressure in units of hPa. The value in volts refers to the voltage at the cathode in volts. Silver and NiCr discs were flat discs, Sn discs were Twin-Mags, ZnAl discs were twin-PLs, while SiAl discs were DCM. Power indicates the power setting. For K11 and K12 cathodes, the ratio of active gas flow to power is about 4.43 ml / kW. In addition, the λ settings for the coating machine are as follows: K15 - 174; K28 - 184; and K29 ​​- 181.

Table 8: Cathodic sputtering - Example 1

<td>Cathode</td><td>Shield</td><td>Power (kW)</td><td>ar</td><td>ABOUT</td><td>N</td><td>Pressure</td><td>Volt</td>

<td>K11</td><td>SiAl</td><td>50</td><td>350</td><td>0</td><td>= + 300</td><td>2.71-03</td><td>242.5</td>

<td>K12</td><td>SiAl</td><td>50</td><td>350</td><td>0</td><td>= + 300</td><td>1.75-03</td><td>251.8</td>

<td>K15</td><td>ZnAl</td><td>51.3</td><td>250</td><td>525</td><td>0</td><td>1.99-03</td><td>279.9</td>

<td>K21</td><td>Ag</td><td>8.0</td><td>150</td><td>0</td><td>0</td><td>1.27-03</td><td>388.6</td>

<td>K25</td><td>NiCr</td><td>18.3</td><td>250</td><td>150</td><td>0</td><td>1.44-03</td><td>510.1</td>

<td>K28</td><td>sn</td><td>29.6</td><td>250</td><td>491</td><td>350</td><td>2.23-03</td><td>260.7</td>

<td>K29</td><td>sn</td><td>31.2</td><td>250</td><td>501</td><td>350</td><td>2.21-03</td><td>257.2</td>

- EP 1673313

<td>K39</td><td>sn</td><td>33.5</td><td>250</td><td>533</td><td>350</td><td>2.27-03</td><td>268.2</td>

<td>K40</td><td>sn</td><td>32.4</td><td>250</td><td>503</td><td>350</td><td>2.36-03</td><td>256.7</td>

<td>K41</td><td>sn</td><td>32.2</td><td>250</td><td>523</td><td>350</td><td>2.53-03</td><td>267.0</td>

<td>K43</td><td>SiAl</td><td>65.0</td><td>350</td><td>0</td><td>371</td><td>2.05-03</td><td>291.5</td>

<td>K46</td><td>ZnAl</td><td>43.5</td><td>250</td><td>545</td><td>0</td><td>1.49-03</td><td>238.5</td>

<td>K49-b</td><td>Ag</td><td>9.5</td><td>150</td><td>0</td><td>0</td><td>1.32-03</td><td>474.1</td>

<td>K50</td><td>NiCr</td><td>17.5</td><td>250</td><td>150</td><td>0</td><td>1.32-03</td><td>498.7</td>

<td>K54</td><td>sn</td><td>46.2</td><td>250</td><td>653</td><td>350</td><td>2.12-03</td><td>311.0</td>

<td>K59</td><td>SiAl</td><td>69.0</td><td>350</td><td>0</td><td>514</td><td>2.78-03</td><td>293.7</td>

<td>K60</td><td>SiAl</td><td>69.0</td><td>350</td><td>0</td><td>514</td><td>3.12-03</td><td>336.0</td>

After cathodic spraying on a glass substrate, example 1 has the following properties after heat treatment with another sheet separated by powder in a standard furnace (heat treatment in an oven with eight heating zones (479, 520, 540, 590, 620, 655, 660, 665 degrees, respectively) C, speed 28 cm / minute):

Table 9: Properties of Example 1 (monolithic; heat treatment)

Property Example 1

Light transmission (Y) (illuminator D65, 10 degrees): 78.86% a * -1.35 b * -0.47

L * 91.17

ΔΕ * about 4-5

Reflection coefficient from the glass substrate (RY) (illuminant D65, 10 7.01% degrees):

a * -2.39 b * 7.25

L * 31.83

ΔΕ * about 2-3

Coefficient of reflection from the shell side (FY) (illuminant D65, 10 degrees): 6.26% a * -10.43 b * 10.27

L * 30.07

R_s (Ω / square) (before heat treatment): about 2.5 to 3

R_s (Ω / square) (after heat treatment): 2.30

Tvis / Rs (after heat treatment): 34.29

Optical turbidity: 0.20

The coated article of example 1 was then laminated onto another glass (e.g.

using PWB or special oil) to form a laminated windshield. The laminated windscreen had the following properties. The laminate is shown in Fig. 3, with

EP 1673313 by coating on surface # 3 (i.e. inner pane). The 'shell side' measurements given in table 10 are taken from the side that would normally be outside the vehicle in normal operation, while the 'windscreen side' measurements are taken from the side that would normally be inside the vehicle, because the shell in this the example is formed on the surface # 3 of the laminate.

Table 10: Properties of Example 1 (laminated; heat treatment)

Property Example 1

Lta (Tvis) (illuminant A, 2 degrees) 76.06%

Light transmission (Y) (illuminator D65, 10 degrees): 76.3% a * -2.59 b * 2.59

L * 90

Reflection coefficient from the glass substrate (RY) (illuminant D65, 10 degrees): 8.65% a * -0.85 b * -7.96

L * 35.30

Coefficient of reflection from the shell side (FY) (illuminant D65, 10 degrees): 8.87% a * -2.19 b * -5.60

L * 35.72

Optical turbidity: 0.33

Rsolar (ISO 9050): 30

Tsolar: 42.5

In addition to the benefits described above, it has surprisingly been found that coated articles according to certain embodiments of the present invention have improved heat-treated properties compared to other known coatings. For example, it has been found that coated articles according to certain embodiments of the present invention can be heat treated in a chamber oven at 650 degrees C for 12 minutes without loss of light transmission above 2% or delamination.

In other words, if a coated (usually monolithic) product is heat treated at about 650 degrees C for 12 minutes, the coated product retains about 98% of its pre-heat light transmittance. The temperature and time values ​​given are exemplary and do not limit the scope of the present invention. These values ​​illustrate improved heat workability (or improved thermal stability) of certain example embodiments of this invention.

As an example of heat treatment, the coated article may be heat treated simultaneously with another glass pane, such that the two glass panes are separated from each other in an oven by a powder known in the art. During the heat treatment, the coated article can be placed in an oven and separated from other glass panes with a powder, such as Separol, known in the art. Thus, according to certain embodiments of the present invention, the thermal stability can be significantly improved.

In the technique of coating glassware, certain terms are used, in particular those defining the properties and sunscreen parameters of coated glass panes.

- EP 1673313

These terms are used in accordance with their accepted meaning (unless otherwise stated) - see patent with serial number 10 / 400,080. The terms "heat treatment" and "heat treated" as used herein mean heating a product to the temperature required for hardening, bending and / or curing a glass-containing product. This definition includes, for example, heating an oven-coated article at a temperature of at least about 580 or 600^aboutC, for the time required to harden bending and / or curing, and also includes specific thermal stability tests at a temperature of about 650 degrees C. In some cases, the heat treatment may take at least about 4 or 5 minutes or longer.

Turbidity means energy dissipation, i.e. the percentage of energy lost due to dissipation. Turbidity can be measured, for example, by the BYK-Gardner optical turbidity meter known in the art.

Although the present invention has been described with reference to a case that is currently regarded as the most practical and preferred embodiment, it is clear that the present invention is not limited to the disclosed embodiment.

"A.TENTOWA" BELLEPAT "LAW OFFICE

Izabela Szych ulska-Hawranek ul Słowackiego 44, 37-700 Przeosi ^ tel tel (016) 7c2-37-77 fax: (016). '. 76-02-87 mobile phone, (0608) 503-081 e-man <a href="mailto:fcellopat@op.pl">fcellopat@op.pl</a> NIP: 795-207-16-72 REGON: 1803505 (6

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<img file="PL1673313T3_D0001.tif" />

EP 1673313